CREATE TABLE  "USERS" 
   (	"ID" NUMBER, 
	"USERNAME" VARCHAR2(10), 
	"PASSWORD" VARCHAR2(10), 
	 CONSTRAINT "USERS_PK" PRIMARY KEY ("ID") ENABLE
   )
/


CREATE OR REPLACE TRIGGER  "BI_USERS" 
  before insert on "USERS"               
  for each row  
begin   
    select "USERS_SEQ".nextval into :NEW.ID from dual; 
end; 

/
ALTER TRIGGER  "BI_USERS" ENABLE
/

INSERT INTO USERS
(ID, USERNAME, PASSWORD)
VALUES (1, 'hr', 'hr')
/

COMMIT
/